KVM: Cache pdptrs

Instead of reloading the pdptrs on every entry and exit (vmcs writes on vmx,
guest memory access on svm) extract them on demand.

Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 18 insertions, 6 deletions

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 522e69597a16..7749b0692cb2 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -777,6 +777,18 @@ static void svm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
         to_svm(vcpu)->vmcb->save.rflags = rflags;
 }
 
+static void svm_cache_reg(struct kvm_vcpu *vcpu, enum kvm_reg reg)
+{
+        switch (reg) {
+        case VCPU_EXREG_PDPTR:
+                BUG_ON(!npt_enabled);
+                load_pdptrs(vcpu, vcpu->arch.cr3);
+                break;
+        default:
+                BUG();
+        }
+}
+
 static void svm_set_vintr(struct vcpu_svm *svm)
 {
         svm->vmcb->control.intercept |= 1ULL << INTERCEPT_VINTR;
@@ -2285,12 +2297,6 @@ static int handle_exit(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
                 }
                 vcpu->arch.cr0 = svm->vmcb->save.cr0;
                 vcpu->arch.cr3 = svm->vmcb->save.cr3;
-                if (is_paging(vcpu) && is_pae(vcpu) && !is_long_mode(vcpu)) {
-                        if (!load_pdptrs(vcpu, vcpu->arch.cr3)) {
-                                kvm_inject_gp(vcpu, 0);
-                                return 1;
-                        }
-                }
                 if (mmu_reload) {
                         kvm_mmu_reset_context(vcpu);
                         kvm_mmu_load(vcpu);
@@ -2641,6 +2647,11 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 
         svm->next_rip = 0;
 
+        if (npt_enabled) {
+                vcpu->arch.regs_avail &= ~(1 << VCPU_EXREG_PDPTR);
+                vcpu->arch.regs_dirty &= ~(1 << VCPU_EXREG_PDPTR);
+        }
+
         svm_complete_interrupts(svm);
 }
 
@@ -2749,6 +2760,7 @@ static struct kvm_x86_ops svm_x86_ops = {
         .set_gdt = svm_set_gdt,
         .get_dr = svm_get_dr,
         .set_dr = svm_set_dr,
+        .cache_reg = svm_cache_reg,
         .get_rflags = svm_get_rflags,
         .set_rflags = svm_set_rflags,